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Commit | Line | Data |
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2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
1da177e4 LT |
2 | /* |
3 | * Berkeley style UIO structures - Alan Cox 1994. | |
1da177e4 | 4 | */ |
607ca46e DH |
5 | #ifndef __LINUX_UIO_H |
6 | #define __LINUX_UIO_H | |
1da177e4 | 7 | |
92236878 | 8 | #include <linux/kernel.h> |
aa28de27 | 9 | #include <linux/thread_info.h> |
607ca46e | 10 | #include <uapi/linux/uio.h> |
1da177e4 | 11 | |
92236878 | 12 | struct page; |
241699cd | 13 | struct pipe_inode_info; |
812ed032 JS |
14 | |
15 | struct kvec { | |
16 | void *iov_base; /* and that should *never* hold a userland pointer */ | |
17 | size_t iov_len; | |
18 | }; | |
19 | ||
00e23707 | 20 | enum iter_type { |
875f1d07 | 21 | /* iter types */ |
8cd54c1c AV |
22 | ITER_IOVEC, |
23 | ITER_KVEC, | |
24 | ITER_BVEC, | |
25 | ITER_PIPE, | |
26 | ITER_XARRAY, | |
27 | ITER_DISCARD, | |
62a8067a AV |
28 | }; |
29 | ||
92236878 | 30 | struct iov_iter { |
8cd54c1c AV |
31 | u8 iter_type; |
32 | bool data_source; | |
92236878 KO |
33 | size_t iov_offset; |
34 | size_t count; | |
62a8067a AV |
35 | union { |
36 | const struct iovec *iov; | |
a280455f | 37 | const struct kvec *kvec; |
62a8067a | 38 | const struct bio_vec *bvec; |
7ff50620 | 39 | struct xarray *xarray; |
241699cd AV |
40 | struct pipe_inode_info *pipe; |
41 | }; | |
42 | union { | |
43 | unsigned long nr_segs; | |
27c0e374 | 44 | struct { |
8cefc107 DH |
45 | unsigned int head; |
46 | unsigned int start_head; | |
27c0e374 | 47 | }; |
7ff50620 | 48 | loff_t xarray_start; |
62a8067a | 49 | }; |
92236878 KO |
50 | }; |
51 | ||
00e23707 DH |
52 | static inline enum iter_type iov_iter_type(const struct iov_iter *i) |
53 | { | |
8cd54c1c | 54 | return i->iter_type; |
00e23707 DH |
55 | } |
56 | ||
57 | static inline bool iter_is_iovec(const struct iov_iter *i) | |
58 | { | |
59 | return iov_iter_type(i) == ITER_IOVEC; | |
60 | } | |
61 | ||
62 | static inline bool iov_iter_is_kvec(const struct iov_iter *i) | |
63 | { | |
64 | return iov_iter_type(i) == ITER_KVEC; | |
65 | } | |
66 | ||
67 | static inline bool iov_iter_is_bvec(const struct iov_iter *i) | |
68 | { | |
69 | return iov_iter_type(i) == ITER_BVEC; | |
70 | } | |
71 | ||
72 | static inline bool iov_iter_is_pipe(const struct iov_iter *i) | |
73 | { | |
74 | return iov_iter_type(i) == ITER_PIPE; | |
75 | } | |
76 | ||
9ea9ce04 DH |
77 | static inline bool iov_iter_is_discard(const struct iov_iter *i) |
78 | { | |
79 | return iov_iter_type(i) == ITER_DISCARD; | |
80 | } | |
81 | ||
7ff50620 DH |
82 | static inline bool iov_iter_is_xarray(const struct iov_iter *i) |
83 | { | |
84 | return iov_iter_type(i) == ITER_XARRAY; | |
85 | } | |
86 | ||
00e23707 DH |
87 | static inline unsigned char iov_iter_rw(const struct iov_iter *i) |
88 | { | |
8cd54c1c | 89 | return i->data_source ? WRITE : READ; |
00e23707 DH |
90 | } |
91 | ||
1da177e4 LT |
92 | /* |
93 | * Total number of bytes covered by an iovec. | |
94 | * | |
95 | * NOTE that it is not safe to use this function until all the iovec's | |
96 | * segment lengths have been validated. Because the individual lengths can | |
97 | * overflow a size_t when added together. | |
98 | */ | |
99 | static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs) | |
100 | { | |
101 | unsigned long seg; | |
102 | size_t ret = 0; | |
103 | ||
104 | for (seg = 0; seg < nr_segs; seg++) | |
105 | ret += iov[seg].iov_len; | |
106 | return ret; | |
107 | } | |
108 | ||
92236878 KO |
109 | static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) |
110 | { | |
111 | return (struct iovec) { | |
112 | .iov_base = iter->iov->iov_base + iter->iov_offset, | |
113 | .iov_len = min(iter->count, | |
114 | iter->iov->iov_len - iter->iov_offset), | |
115 | }; | |
116 | } | |
117 | ||
f0b65f39 AV |
118 | size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, |
119 | size_t bytes, struct iov_iter *i); | |
92236878 | 120 | void iov_iter_advance(struct iov_iter *i, size_t bytes); |
27c0e374 | 121 | void iov_iter_revert(struct iov_iter *i, size_t bytes); |
8409a0d2 | 122 | int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes); |
92236878 | 123 | size_t iov_iter_single_seg_count(const struct iov_iter *i); |
6e58e79d AV |
124 | size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, |
125 | struct iov_iter *i); | |
f0d1bec9 AV |
126 | size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, |
127 | struct iov_iter *i); | |
aa28de27 AV |
128 | |
129 | size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); | |
130 | size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); | |
aa28de27 | 131 | size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i); |
aa28de27 AV |
132 | |
133 | static __always_inline __must_check | |
134 | size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) | |
135 | { | |
136 | if (unlikely(!check_copy_size(addr, bytes, true))) | |
c43aeb19 | 137 | return 0; |
aa28de27 AV |
138 | else |
139 | return _copy_to_iter(addr, bytes, i); | |
140 | } | |
141 | ||
142 | static __always_inline __must_check | |
143 | size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) | |
144 | { | |
145 | if (unlikely(!check_copy_size(addr, bytes, false))) | |
c43aeb19 | 146 | return 0; |
aa28de27 AV |
147 | else |
148 | return _copy_from_iter(addr, bytes, i); | |
149 | } | |
150 | ||
151 | static __always_inline __must_check | |
152 | bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) | |
153 | { | |
4b6c132b AV |
154 | size_t copied = copy_from_iter(addr, bytes, i); |
155 | if (likely(copied == bytes)) | |
156 | return true; | |
157 | iov_iter_revert(i, copied); | |
158 | return false; | |
aa28de27 AV |
159 | } |
160 | ||
161 | static __always_inline __must_check | |
162 | size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) | |
163 | { | |
164 | if (unlikely(!check_copy_size(addr, bytes, false))) | |
c43aeb19 | 165 | return 0; |
aa28de27 AV |
166 | else |
167 | return _copy_from_iter_nocache(addr, bytes, i); | |
168 | } | |
169 | ||
170 | static __always_inline __must_check | |
171 | bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) | |
172 | { | |
4b6c132b AV |
173 | size_t copied = copy_from_iter_nocache(addr, bytes, i); |
174 | if (likely(copied == bytes)) | |
175 | return true; | |
176 | iov_iter_revert(i, copied); | |
177 | return false; | |
aa28de27 AV |
178 | } |
179 | ||
0aed55af DW |
180 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
181 | /* | |
182 | * Note, users like pmem that depend on the stricter semantics of | |
183 | * copy_from_iter_flushcache() than copy_from_iter_nocache() must check for | |
184 | * IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) before assuming that the | |
185 | * destination is flushed from the cache on return. | |
186 | */ | |
6a37e940 | 187 | size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i); |
0aed55af | 188 | #else |
6a37e940 LT |
189 | #define _copy_from_iter_flushcache _copy_from_iter_nocache |
190 | #endif | |
191 | ||
ec6347bb DW |
192 | #ifdef CONFIG_ARCH_HAS_COPY_MC |
193 | size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i); | |
8780356e | 194 | #else |
ec6347bb | 195 | #define _copy_mc_to_iter _copy_to_iter |
8780356e DW |
196 | #endif |
197 | ||
6a37e940 LT |
198 | static __always_inline __must_check |
199 | size_t copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) | |
0aed55af | 200 | { |
6a37e940 | 201 | if (unlikely(!check_copy_size(addr, bytes, false))) |
c43aeb19 | 202 | return 0; |
6a37e940 LT |
203 | else |
204 | return _copy_from_iter_flushcache(addr, bytes, i); | |
0aed55af | 205 | } |
6a37e940 | 206 | |
8780356e | 207 | static __always_inline __must_check |
ec6347bb | 208 | size_t copy_mc_to_iter(void *addr, size_t bytes, struct iov_iter *i) |
8780356e | 209 | { |
dfb06cba | 210 | if (unlikely(!check_copy_size(addr, bytes, true))) |
8780356e DW |
211 | return 0; |
212 | else | |
ec6347bb | 213 | return _copy_mc_to_iter(addr, bytes, i); |
8780356e DW |
214 | } |
215 | ||
c35e0248 | 216 | size_t iov_iter_zero(size_t bytes, struct iov_iter *); |
886a3911 | 217 | unsigned long iov_iter_alignment(const struct iov_iter *i); |
357f435d | 218 | unsigned long iov_iter_gap_alignment(const struct iov_iter *i); |
aa563d7b | 219 | void iov_iter_init(struct iov_iter *i, unsigned int direction, const struct iovec *iov, |
71d8e532 | 220 | unsigned long nr_segs, size_t count); |
aa563d7b | 221 | void iov_iter_kvec(struct iov_iter *i, unsigned int direction, const struct kvec *kvec, |
05afcb77 | 222 | unsigned long nr_segs, size_t count); |
aa563d7b | 223 | void iov_iter_bvec(struct iov_iter *i, unsigned int direction, const struct bio_vec *bvec, |
abb78f87 | 224 | unsigned long nr_segs, size_t count); |
aa563d7b | 225 | void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode_info *pipe, |
241699cd | 226 | size_t count); |
9ea9ce04 | 227 | void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count); |
7ff50620 DH |
228 | void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray, |
229 | loff_t start, size_t count); | |
7b2c99d1 | 230 | ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, |
2c80929c | 231 | size_t maxsize, unsigned maxpages, size_t *start); |
91f79c43 AV |
232 | ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, |
233 | size_t maxsize, size_t *start); | |
f67da30c | 234 | int iov_iter_npages(const struct iov_iter *i, int maxpages); |
92236878 | 235 | |
4b8164b9 AV |
236 | const void *dup_iter(struct iov_iter *new, struct iov_iter *old, gfp_t flags); |
237 | ||
b57332b4 | 238 | static inline size_t iov_iter_count(const struct iov_iter *i) |
92236878 KO |
239 | { |
240 | return i->count; | |
241 | } | |
242 | ||
0b86dbf6 AV |
243 | /* |
244 | * Cap the iov_iter by given limit; note that the second argument is | |
245 | * *not* the new size - it's upper limit for such. Passing it a value | |
246 | * greater than the amount of data in iov_iter is fine - it'll just do | |
247 | * nothing in that case. | |
248 | */ | |
249 | static inline void iov_iter_truncate(struct iov_iter *i, u64 count) | |
0c949334 | 250 | { |
0b86dbf6 AV |
251 | /* |
252 | * count doesn't have to fit in size_t - comparison extends both | |
253 | * operands to u64 here and any value that would be truncated by | |
254 | * conversion in assignement is by definition greater than all | |
255 | * values of size_t, including old i->count. | |
256 | */ | |
0c949334 AV |
257 | if (i->count > count) |
258 | i->count = count; | |
259 | } | |
260 | ||
b42b15fd AV |
261 | /* |
262 | * reexpand a previously truncated iterator; count must be no more than how much | |
263 | * we had shrunk it. | |
264 | */ | |
265 | static inline void iov_iter_reexpand(struct iov_iter *i, size_t count) | |
266 | { | |
267 | i->count = count; | |
268 | } | |
52cbd23a WB |
269 | |
270 | struct csum_state { | |
271 | __wsum csum; | |
272 | size_t off; | |
273 | }; | |
274 | ||
275 | size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csstate, struct iov_iter *i); | |
a604ec7e | 276 | size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); |
4b6c132b AV |
277 | |
278 | static __always_inline __must_check | |
279 | bool csum_and_copy_from_iter_full(void *addr, size_t bytes, | |
280 | __wsum *csum, struct iov_iter *i) | |
281 | { | |
282 | size_t copied = csum_and_copy_from_iter(addr, bytes, csum, i); | |
283 | if (likely(copied == bytes)) | |
284 | return true; | |
285 | iov_iter_revert(i, copied); | |
286 | return false; | |
287 | } | |
d05f4435 SG |
288 | size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, |
289 | struct iov_iter *i); | |
b42b15fd | 290 | |
bfdc5970 CH |
291 | struct iovec *iovec_from_user(const struct iovec __user *uvector, |
292 | unsigned long nr_segs, unsigned long fast_segs, | |
293 | struct iovec *fast_iov, bool compat); | |
294 | ssize_t import_iovec(int type, const struct iovec __user *uvec, | |
295 | unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, | |
296 | struct iov_iter *i); | |
297 | ssize_t __import_iovec(int type, const struct iovec __user *uvec, | |
298 | unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, | |
299 | struct iov_iter *i, bool compat); | |
bc917be8 AV |
300 | int import_single_range(int type, void __user *buf, size_t len, |
301 | struct iovec *iov, struct iov_iter *i); | |
302 | ||
812ed032 | 303 | #endif |